<template>
	<view>
		<my-search @click="gotoSearch"></my-search>
		<view class="scroll-view-container">
			<!-- 左侧的滚动视图区域 -->
			<scroll-view class="left-scroll-view" scroll-y :style="{height: wh +'px'}">
				<block v-for="(item,i) in cateList" :key="i">
					<view class="left-scroll-view-item" :class="i === active ? 'active' : ''" @click="activeChanged(i)">
						{{item.cat_name}}
					</view>
				</block>
			</scroll-view>
			<!-- 右侧的滚动视图区域 -->
			<scroll-view class="right-scroll-view" scroll-y :style="{height: wh +'px'}" :scroll-top="scrollTop">				
				<block v-for="(p,s) in Level2List " :key="s">
					<view class="cate-lv2-title">{{p.cat_name}}</view>
					<!-- 动态渲染三级分类的列表数据 -->
					<view class="cate-lv3-list">
						<view class="cate-lv3-item" v-for="(a,b) in p.children" :key="b" @click="gotoGoodsList(a)">
							<image :src="a.cat_icon"></image>
							<text>{{a.cat_name}}</text>
						</view>
					</view>
				</block>
			</scroll-view>
		</view>

	</view>
</template>

<script>
	export default {
		data() {
			return {
				// 窗口的可用高度 = 屏幕高度 - navigationBar高度 - tabBar 高度
				wh: 0,
				active: 0,
				cateList: [],
				Level2List: [],
				// 滚动条距离顶部的距离
				scrollTop: 0
			};
		},
		onLoad() {
			// 获取当前系统的信息
			const sysInfo = uni.getSystemInfoSync()
			// 为 wh 窗口可用高度动态赋值
			this.wh = sysInfo.windowHeight - 50
			this.getCateList()

		},
		methods: {
			async getCateList() {
				const res = await uni.$http.get('cate')
				if (res.statusCode !== 200) {
					return uni.$showMsg()
				}
				this.cateList = res.data;
				 // console.log(this.cateList)
				this.Level2List = this.cateList[0].children;
			},
			activeChanged(i) {
				this.active = i;
				this.Level2List = this.cateList[i].children;
				// 让 scrollTop 的值在 0 与 1 之间切换
				this.scrollTop = this.scrollTop === 0 ? 1 : 0
			},
			gotoGoodsList(item) {
				// console.log(item)
				uni.navigateTo({
					url: '/subpkg/goods_list/goods_list?cid=' + item.cat_id
				})
			},
			gotoSearch(){
				uni.navigateTo({
					url: '/subpkg/search/search'
				})
			}
		}
	}
</script>

<style lang="less">
	.scroll-view-container {
		display: flex;

		.left-scroll-view {
			width: 120px;

			.left-scroll-view-item {
				line-height: 60px;
				background-color: #c00000;
				text-align: center;
				font-size: 12px;
				color: white;
			}

			.active {
				background-color: #ffffff;
				position: relative;
				color: black;
			}

			.active::before {
				content: '';
				display: block;
				width: 3px;
				height: 30px;
				background-color: #c00000;
				position: absolute;
				left: 0;
				top: 50%;
				transform: translateY(-50%);
			}
		}

		.right-scroll-view {
			.cate-lv2-title {
				font-size: 12px;
				font-weight: bold;
				text-align: center;
				padding: 15px 0;
			}

			.cate-lv3-list {
				display: flex;
				flex-wrap: wrap;

				.cate-lv3-item {
					width: 33.33%;
					margin-bottom: 10px;
					display: flex;
					flex-direction: column;
					align-items: center;

					image {
						width: 60px;
						height: 60px;
					}

					text {
						font-size: 12px;
					}
				}
			}
		}

	}
</style>
